The invention relates to a commutator motor with an insulating cover for the rotor shaft.
It is known, for instance, from DE-GM No. 18 38 776, that, after taking into consideration the respective tolerances of the individual parts, in order to achieve a defined axial play in the rotor support of a miniature motor, the axial distance between the axially outer end face of the commutator and the rotor stack end face facing away from the commutator or the insulating end washer, which may optionally cover this end face, should be constant. This necessitates that after the rotor stack is fastened to the rotor shaft and optionally, the insulating end washers are slipped on, the commutator is pressed to a different axial depth, corresponding to the compensation of the tolerances, onto the uninsulated rotor shaft end; then, there remains, as a rule, a rotor shaft region which is different from motor to motor, which depends in each case on the tolerances of the assembled rotor parts, and which is basically uninsulated. This rotor shaft region extends between the one rotor stack end face and the opposite commutator end face. If there is a danger, expecially if the commutator is contacted with the so-called backside winding technique, preferably in connection with angled rotor lamination stacks, that this bare rotor shaft region may be touched by the winding wires between the coil heads of the rotor winding and the hooks of the commutator, this rotor shaft region must be electrically insulated at its outer circumference. In the known case the electrical insulation is done after the commutator is secure at the correct distance by wrapping the bare rotor shaft region with insulating tape by hand.